Long -Range Production Planning Of Direct-Shipping Ore From Several Deposits

Production planning of direct-shipping ore from a number of relatively small deposits serves to sequence development and mining of these deposits so that both long- and short-range demand can be met while the timing of development cost is such that the average annual rate is minimized. Hand-computed methods have the disadvantage that they require substantial effort and time and cannot be exhaustive. The application of operations research and computers not only overcomes these disadvantages, but opens up additional applications, such as feasibility studies involving alternative mining strategies and changes in the ore market. The method employed concerns linear programming and specifically the Big-M algorithm applied to the variant on the simplex technique with penalties applied to deviations from the desired ore grade. Acceptable 20-year production schedules could be generated in relatively little time, i. e. , in less than 200 seconds for the central processor of the Control Data Corporation 6400 system of the University of Colorado in Boulder.